Self-healing resin

ABSTRACT

A self-healing paint composition includes water, a self-healing polymer having a first functional group and a second functional group bonded thereto that interact with each other by dynamic covalent or dynamic non-covalent interactions, and one or more optional pigment compositions. At least one of the first functional group and the second functional group are present in an amount of 0.1 to 10 mole percent the emulsion self-healing polymer having a weight average molecular weight of about 15,000 g/mol to 1,000,000 g/mol.

TECHNICAL FIELD

In at least one embodiment, the present invention is related to paintcompositions that include a self-healing resin.

BACKGROUND

Paint coatings are ubiquitous finding numerous applications for bothaesthetic and functional applications. In many applications, paintcoatings are applied to improve the aesthetic appeal of a surface byproviding a uniform and pleasing appearance. In addition to aesthetics,paint coating can provide protection to the underlying substrate.However, when a painted substrate is damaged it must often be recoatedwith new material. If a coating could automatically repair inflicteddamage it would dramatically increase its durability and lifetime.

Accordingly, there is a need for paint compositions the ability toself-repair and protect the underlying coated substrate.

SUMMARY

The present invention solves one or more problems of the prior art byproviding in at least one embodiment, a self-healing resin. Theself-healing resin includes a self-healing polymer having a firstfunctional group and a second functional group bonded thereto thatinteract with each other by dynamic covalent or dynamic non-covalentinteractions. Characteristically, the first functional group is presentin an amount of 0.1 to 10 mole percent the self-healing polymer having aweight average molecular weight of about 15,000 g/mol to 1,000,000g/mol. The weight average molecular weight of the self-healing polymeris such that the self-healing polymer dissolves in acetone withsolubility greater than 0.1 g/ml at 25° C.

In another embodiment, a paint composition that includes theself-healing resin is provided. The paint composition includes water, aself-healing polymer having a first functional group and a secondfunctional group bonded thereto that interact with each other by dynamiccovalent or dynamic non-covalent interactions, and one or more optionalpigment compositions. At least one of the first functional group and thesecond functional group are present in an amount of 0.1 to 10 molepercent the emulsion self-healing polymer having a weight averagemolecular weight of about 15,000 g/mol to 1,000,000 g/mol. The weightaverage molecular weight of the self-healing polymer is such that theself-healing polymer dissolves in acetone with solubility greater than0.1 g/ml at 25° C.

DETAILED DESCRIPTION

Reference will now be made in detail to presently preferredcompositions, embodiments and methods of the present invention, whichconstitute the best modes of practicing the invention presently known tothe inventors. The Figures are not necessarily to scale. However, it isto be understood that the disclosed embodiments are merely exemplary ofthe invention that may be embodied in various and alternative forms.Therefore, specific details disclosed herein are not to be interpretedas limiting, but merely as a representative basis for any aspect of theinvention and/or as a representative basis for teaching one skilled inthe art to variously employ the present invention.

Except in the examples, or where otherwise expressly indicated, allnumerical quantities in this description indicating amounts of materialor conditions of reaction and/or use are to be understood as modified bythe word “about” in describing the broadest scope of the invention.Practice within the numerical limits stated is generally preferred.Also, unless expressly stated to the contrary: percent, “parts of,” andratio values are by weight; the term “polymer” includes “oligomer,”“copolymer,” “terpolymer,” and the like; molecular weights provided forany polymers refers to weight average molecular weight unless otherwiseindicated; the description of a group or class of materials as suitableor preferred for a given purpose in connection with the inventionimplies that mixtures of any two or more of the members of the group orclass are equally suitable or preferred; description of constituents inchemical terms refers to the constituents at the time of addition to anycombination specified in the description, and does not necessarilypreclude chemical interactions among the constituents of a mixture oncemixed; the first definition of an acronym or other abbreviation appliesto all subsequent uses herein of the same abbreviation and appliesmutatis mutandis to normal grammatical variations of the initiallydefined abbreviation; and, unless expressly stated to the contrary,measurement of a property is determined by the same technique aspreviously or later referenced for the same property.

It is also to be understood that this invention is not limited to thespecific embodiments and methods described below, as specific componentsand/or conditions may, of course, vary. Furthermore, the terminologyused herein is used only for the purpose of describing particularembodiments of the present invention and is not intended to be limitingin any way.

It must also be noted that, as used in the specification and theappended claims, the singular form “a,” “an,” and “the” comprise pluralreferents unless the context clearly indicates otherwise. For example,reference to a component in the singular is intended to comprise aplurality of components.

The term “comprising” is synonymous with “including,” “having,”“containing,” or “characterized by.” These terms are inclusive andopen-ended and do not exclude additional, unrecited elements or methodsteps.

The phrase “consisting of” excludes any element, step, or ingredient notspecified in the claim. When this phrase appears in a clause of the bodyof a claim, rather than immediately following the preamble, it limitsonly the element set forth in that clause; other elements are notexcluded from the claim as a whole.

The phrase “consisting essentially of” limits the scope of a claim tothe specified materials or steps, plus those that do not materiallyaffect the basic and novel characteristic(s) of the claimed subjectmatter.

The terms “comprising”, “consisting of”, and “consisting essentially of”can be alternatively used. When one of these three terms is used, thepresently disclosed and claimed subject matter can include the use ofeither of the other two terms.

Throughout this application, where publications are referenced, thedisclosures of these publications in their entireties are herebyincorporated by reference into this application to more fully describethe state of the art to which this invention pertains.

In one embodiment, a self-healing resin is provided. The self-healingresin avoids the need of recoating a substrate by providing a coatingthat automatically repairs damage. Advantageously, the self-healingresin uses dynamic covalent or dynamic non-covalent interactions areincorporated into a latex emulsion polymer through the use of specialtymonomers. Examples of such interactions include, but are not limited to,hydrogen bonding, electrostatic, metal-ligand, reversible covalentbonds, and the like. These interactions can be triggered by an externalstimulus (e.g., light, heat, redox, pH, etc.) or are completelyautomatic.

In a variation, the self-healing paint composition includes water, aself-healing polymer having a first functional group and a secondfunctional group bonded to the self-healing polymer. The first andsecond functional groups interact with each other by dynamic covalent ordynamic non-covalent interactions, and one or more optional pigmentcompositions. The first functional group is present in an amount of 0.1to 10 mole percent the self-healing polymer having a weight averagemolecular weight of about 15,000 g/mol to 1,000,000 g/mol, as measuredas THF using gel permeation chromatography. In a refinement, the weightaverage molecular weight of the self-healing polymer is such that theself-healing polymer dissolves in acetone with solubility greater than0.1 g/ml at 25° C. In this context, the mole percent is the number ofmoles of the first functional group in one mole of self-healing polymerdivided by one mole of self-healing polymer times 100 percent. In arefinement, the first functional group is present in an amount inincreasing order of preference of 0.05, 0.1, 0.2, 0.3, or 2 mole percentand in an amount less than, in increasing order of preference, 20, 15,10, 8, 6, or 5 mole percent.

Typically, the weight average molecular weight of the self-healingpolymer is less than 1,000,000. In a refinement, the weight averagemolecular weight of the self-healing polymer is less than increasingorder of preference, 2,000,000; 1,000,000; 750,000; 500,000; or 300,000and greater than in increasing order of preference, 50,000; 70,000;100,000; 150,000; or 200,000. Not sure that this is a key point. Themolecular weight should be low enough that the polymer can flow atelevated temperature. In one variation, the molecular weight of theself-healing polymer chains is lowered so that they are not physicallycross-linked by chain entanglements. In a refinement, the self-healingpolymer is formed in the presence of a chain transfer agent (CTA) toreduce the molecular weight of the self-healing polymer chains. For thisvariation, the molecular weight range is controlled by the level of CTAused, and a steady decrease in molecular weight is observed withincreasing CTA percentage. Therefore, the self-healing polymer includesthe residues of such chain transfer agents. Typically, the chaintransfer agent is a C₁₋₁₅ thiol. Examples of the chain transfer agentinclude, but are not limited to, from the group consisting ofoctanethiol, butanethiol, thioglycolic acid, Z-thioethanol,methanethiol, ethanethiol, propanethiol, pentanethiol, hexanethiol,heptanethiol, nonanethiol, decanethiol, dodecanethiol, and combinationsthereof.

As set forth above, the self-healing polymer is advantageously anemulsion polymer. Suitable emulsion polymers include, but are notlimited to, monomers or functionalized monomers selected from acrylicpolymers, vinyl acrylic copolymers, ethylene-vinyl acetate copolymers,styrene-acrylic copolymers, polyvinyl alcohol, and combinations thereof.Suitable film forming polymers are formed from one or more monomersselected from the group consisting of methacrylate, methyl acrylate,ethyl acrylate, 2-chloroethyl vinyl ether, 2-ethylhexyl acrylate,hydroxyethyl methacrylate, butyl acrylate, butyl methacrylate,trimethylolpropane triacrylate, pentafluorophenyl methacrylate,pentafluorophenyl acrylate, 1,1,1,3,3,3-hexafluoroisopropyl acrylate,bis-(2,2,2-trifluoroethyl) itaconate,bis-(1,1,1,3,3,3-hexafluoroisopropyl), 1H,1H,3H-hexafluorobutylacrylate, 1H,1H,7H-dodecafluoroheptyl methacrylate, 2,2,2-trifluoroethylacrylate, 2,2,2-trifluoroethyl methacrylate, aliphatic, fluorinatedaliphatic, 1H,1H,2H,2H-Heptadecafluorodecyl methacrylate 532.2 acrylic,1H,1H,2H,2H-heptadecafluorodecyl acrylate, 1H,1H,5H-octafluoropentylacrylate, 1H,1H,3H-tetrafluoropropyl methacrylate,hexafluoro-iso-propyl, 1H,1H,3H-hexafluorobutyl methacrylate,1H,1H,5H-octafluoropentyl methacrylate, ethylene, propylene, 1-butylene,2 butylene, vinyl acetate, and combinations thereof. The monomers whenfunctionalized can be functionalized with OH, halo, or combinationsthereof.

Typically, the paint composition includes the emulsion polymer in anamount from about 25 to 60 weight percent of the total weight of thepaint composition and the optional pigments in an amount from about 5 to40 weight percent of the total weight of the paint composition with thebalance being water. In another embodiment, the paint compositionincludes the self-healing polymer in an amount from about 40 to 50weight percent of the total weight of the paint composition, theoptional pigments in an amount from about 10 to 30 weight percent of thetotal weight with the balance being water.

As set forth above, the paint composition optionally includes one ormore pigments. Suitable pigments are azo dyes, phthalocyanine,anthraquinone dyes, titanium oxide, calcium carbonate, iron oxides(black, yellow and red), zinc oxide and carbon black, powdered metals,metal compounds (e.g., zinc phosphate), and combinations thereof. In avariation, the paint composition can include a matting agent to adjustthe gloss to a lower sheen. The matting agent can be any extenderpigment that does not add opacity to the clear coat, such as silicas,nepheline syenite, and the like. In a refinement, the matting agent ispresent in an amount from about 0.2 to 10 percent of the dry weight ofthe paint composition. In a variation, some paint compositions may notcontain pigment, such as, for example, a self-healing high gloss clearcoating.

In some variations, the paint composition further includes one or moreadditives selected from the group consisting of rheology modifiers,surfactants, defoamers, organic solvents, pH adjusters, UV stabilizers,dispersants, coalescents, biocides, inorganic pigment, organic pigments,and combinations thereof. Typically, the additives are present in anamount from about 0.1 to 20 weight percent of the total weight of thepaint composition. Examples of surfactants commonly used in emulsionpolymerization include, but are not limited to fatty acids, sodiumlauryl sulfate, and alpha olefin sulfonate.

The following examples illustrate the various embodiments of the presentinvention. Those skilled in the art will recognize many variations thatare within the spirit of the present invention and scope of the claims.

Dynamic Non-Covalent Self-Healing

In order to prepare dynamic non-covalent self-healing resins, themolecular weight of the emulsion polymer was reduced using a chaintransfer agent. This decrease in molecular weight allowed for increasedchain mobility at elevated temperature, resulting in self-healingbehavior. In order to increase hardness and physical properties lost byreduced molecular weight, dynamic non-covalent cross-links wereintroduced throughout the film by utilizing methacrylamide copolymerizedinto the polymer. The methacrylamide functionality provided thenecessary hydrogen bonding to increase hardness and improve physicalproperties while still being dynamic at elevated temperature.

Dynamic Covalent Self-Healing

Similar to the case of the dynamic non-covalent resin, the molecularweight was lowered using a chain transfer agent. Then a cross-linkablefunctionality, furfuryl methacrylate (FM) was copolymerized into theresin. This functionality could be cross-linked with a bismaleimide toform the Diels-Alder adduct. The Diels-Alder adduct is reversible atelevated temperature but stable at room temperature and is more solventresistant than hydrogen bonds, due to the covalent bonds. Thebismaleimide used in this case was1,1′-(methylenedi-4,1-phenylene)bismaleimide due to its availabilityfrom commercial sources. Unfortunately, this molecule was not watersoluble and could not be added directly to the resin. The intent is thatthe bismaleimide is water soluble, can be added to the resin and willnot react until evaporation of the water and coalescence of the emulsionpolymers is complete. In this case, the bismaleimide would crash out ofthe water phase when added to the self-healing emulsion. To overcomethis and prove the concept, the self-healing emulsion with loweredmolecular weight and containing furfuryl methacrylate was first dried toform a film. The resulting solid was then dissolved in THF or DMF (asolvent that 1,1′-(Methylenedi-4,1-phenylene) bismaleimide is solublein). Then the bismaleimide pre-dissolved in THF or DMF was added to thedissolved self-healing polymer and the mixture was cast. Upon drying thecovalent cross-links formed through the Diels-Alder reaction. Uponscratching and heating at elevated temperatures the scratches wouldheal.

Control Resin Synthesis

The control resin was synthesized in accordance to the recipe set forthin Table 1.

TABLE 1 Control composition Control Loading Name (g) Monomer CompositionMonomer 1 Butyl acrylate, (BA) 223.0 Monomer 2 Methyl methacrylate,(MMA) 262.9 Monomer 3 Methacrylic acid, (MAA) 5.0 Monomer 4Methacrylamide, (MA) — Monomer 5 Furfuryl Methacrylate, (FM) — TotalMonomer 490.9 Other Ingredients Emulsifier Rhodacal DS-10 (Solvay Inc.)5.9 Initiator Sodium persulfate (SPS) 1.2 Base/Buffer Sodium carbonate2.0 Defoamer BYK-022 0.1 Water DI water 496. Chaser (reducer) BruggolitFF6M 1.9 Chaser (oxidizer) Tert-butyl hydroperoxide 2.0 solution Chaintransfer agent 1-dodecanethiol (DDT) — (CTA) Total weight (g) 1000.0

Self-Healing Resin Preparation Procedure 1 Step I: Pre-EmulsionPreparation

The pre-emulsion was made in a conical flask with 1000 mL capacity. 250mL water was added to 1 g of sodium carbonate followed by 4 g of DS-10surfactant and stirred at 150 rpm using an overhead stirrer. Whilestirring at 150 rpm, 223.0 g n-butyl acrylate and 262.9 g of methylmethacrylate were added. The speed was then increased to 600 rpm andthen 5.0 g of methacrylic acid was added. The mixture was then stirredat 850 rpm for 30 min.

Step II: Reactor Set Up

In a 2.5 L reactor was added 176 mL water, 1.0 g of sodium carbonate,and 1.9 g of DS-10. The reactor is then set to a temperature of 82-86°C. stirred at 150 rpm.

Step III: Initiator and Chaser Preparation

The initiator solution was prepared by adding 1.2 g of sodium persulfateto 50 mL water. The chaser was prepared by adding 1.9 g of BruggolitFF6M to 10 mL water and 2.0g of tert-butyl hydroperoxide (70% solutionin water) to 10 mL of water.

Step IV: Addition of Reactants and Conditions

The seeding step was performed by adding 4% pre-emulsion and 4%initiator to the reactor. The mixture was stirred at 86° C. for 30 min.The solution showed a purple/blue tint, confirming initiation of thereaction.

The remaining 96% of the pre-emulsion was added over 3 hours usingperistaltic pump and the initiator added over 3 hours 15 minutes viasyringe pump. The addition was performed at 175 RPM and 82-86° C. Aftercomplete addition the mixture was stirred an additional 30 minutes at82-86° C. The reactor temperature was lowered to 55-60° C. and then thechaser was added over 10 min and mixture kept at 50-60° C. for 30minutes. The heat was removed and then 0.1 g of BYK-022 defoamer wasadded. The resin was filtered via 150-200 micron mesh and the followingQC properties were measured: VOC, pH, particle size and % Solid.

Self-Healing Resin Preparation Procedure 2 Step-I , II & III: Common forall the Procedures

Pre-emulsion, initiator and reactor charge will get prepared by asimilar method as set forth above.

Step-IV- Polymerization

In this step, 5% pre-emulsion and 40% initiator are added dropwise intothe reactor by addition funnel when the temperature of the reactor reachto 84-86° C. About 1 drop of the pre-emulsion and initiator are addedsimultaneously in the reactor. Once the pre-emulsion (PE) is finishedcontinue addition of initiator till it get finished. The reaction isallowed to continue for next 20 min after complete addition ofinitiator. Any remaining PE and initiator are added to the reactor withabout 1 drop of initiator being added in the reactor after 30 drops ofpre-emulsion. 1-2 drop of pre-emulsion will take 2 seconds to get addedin the reactor with addition funnel hence 1 drop of initiator will getadded in the reactor in nearly 45 Sec to 1 minute. The addition ofpre-emulsion will take about 3 hours while the initiator will take about3 to 3 hr:15 min. Once completed, the initiator is added in the reactorwhile allowing the reaction to continue at 84-86° C. for another 30 min.The reactor is prepared for addition of the chaser by lowering thekettle temperature to 55-60° C.

Step-V-Chaser Addition

Prepare the solutions as set forth above. The reducing and oxidizingagent are added simultaneously in the reactor with an addition funnel insuch a way that the addition is completed within 10 min.

The reaction is allowed to continue at 55-60° C. for 30 min. The heatingis then stopped with stirring continuing until the kettle reaches roomtemperature. Defoamer BYK022 is added in an amount of 0.1gm for 1000 mLreaction with stirring continuing for 10 min. The resin is filtered with150-200 micron filter. Quality control procedures are used to determinethe about solids, pH, particle size and specific weight.

Self-Healing Resin Preparation Procedure 3

A Self-healing latex emulsion polymer is also prepared by changing themanner in which polyethylene (PE) and initiator are added to thereactor. In this variation, nitrogen is used to degas the deionizedwater. A kettle charge is prepared by combining 1.59 g DS-10, 1 g sodiumcarbonate, and 176 g deionized water and then mixing at 150 RPM to mixand dissolve all ingredients. Nitrogen gas is used to purge the reactionkettle and keep the kettle free of oxygen. A monomer pre-emulsion isprepared by premixing 250 g deionized water, 4 g DS-10, and 1 g sodiumcarbonate, mix it at 150-200 RPM. The monomer butyl acrylate is addedand the stirring speed increased to 600 RPM. The monomer methylmethacrylate is then added and the stirring speed increased to 850-900RPM. Next, the monomer methacrylic acid is added. Dodecanethiol is addedin 2 fractions during the reaction after pre-seeding. Preparation of thepre-emulsion is completed by mixing at 850-900 RPM for 20-30 minutes. Aninitiator solution is prepared by dissolving 1.5 g sodium persulfate in50 g DI water. A chaser solution is prepared by dissolving 1.89 gBruggolit FF6M in 10 g water and by diluting 2.0 g tent-butylhydroperoxide solution in 10 g water.

Polymerization is then accomplished by pre-seeding in which the kettleis heated to 82-86° C. with stirring at 175-178 RPM. About 20.6 g (40%total amount) sodium persulfate solution (SPS) and 75 g (about 10% totalamount) monomer pre-emulsion are added to kettle under mixing at 150-175RPM by addition funnel. The rate of initiator addition should be doublethat of the pre-emulsion and the rest of the initiator is added in thereactor continuously. The complete addition will take about 45 min. Thekettle temperature is maintained within the 82-86° C. range with thepre-seeding being held for 20 minutes. Continuous polymerization isaccomplished by keeping the temperature at 82-84° C. while feeding themonomer pre-emulsion (as percentage of the total amount:10%+50%+20%+20%) and sodium persulfate initiator solution simultaneouslybut independently. Both solutions are fed at a constant rate over 3hours. The chain transfer agent is added in two fractions. First, 50%chain transfer agent is added after 60% of pre-emulsion addition (10% ofpre-seeding+50%) by continuous drop method with addition funnel. Theremainder of the chain transfer agent is added after 80% pre-emulsionaddition (10%+50%+20%) of the total percentage of the chain transferagent), keep the reaction for 30 min. after completing PE and SPSfeeding. At this point, the mixing speed can be raised up to 250 RPMwith the latex viscosity rising and the mixer position should beadjusted with pre-emulsion feeding. After cooling down the batch to55-60 ° C., the Bruggolit FF6M and the tent-butyl hydroperoxide chasersolutions are added separately and simultaneously over 10 min. Afteradding all the FF6M and tent-butyl hydroperoxide solutions to thekettle, the reaction continued for 30 min. Heating is then stopped toallow the reactor to attain room temperature. About 0.1 g BYK-022 isadded to the batch (if required) and mixed for 15 min. The latex levelin the kettle will decrease with de-foaming during this time. A 200micron filter is used to filter the latex when transferring the latexfrom the reactor to a storage container or tank. The latex in solids,the pH, the particle size and specific weight are verified.

Example of Low Molecular Weight Self-Healing Resin Synthesis

The control procedure was followed, except that 24.5 g ofn-dodecanethiol was added to the pre emulsion.

Example of Low Molecular Weight Non-Covalent (Hydrogen Bonding)Self-Healing Resin Synthesis

The control procedure was followed, except that 24.5 g ofn-dodecanethiol and 4.9 g of methacrylamide were added to the preemulsion.

Example of Low Molecular Weight Dynamic Covalent (Diels-Alder)Self-Healing Resin Synthesis

The control procedure was followed, except that 24.5 g ofn-dodecanethiol and 12.25 g of furfuryl methacrylate were added to thepre emulsion.

Evaluation of Self-Healing Performance of Resin

To evaluate self-healing performance, a film (6-7 mil dry filmthickness, 12 mil wet) was applied on a metal panel and dried for 24hrs. to 3 days. The film was then scratched without damaging theunderlying metal substrate and heated using a hair dryer, hot plate, oroven set at 60° C. The scratches disappearance time was recorded. Table2 provides a summary of the non-covalent self-healing resins tested.Table 3 provides a summary of self-healing properties for these resins.Table 4 provides a summary of the hardness results while Table 5provides a summary of the self-healing properties of these resins.Self-healing was determined on a LENETA Chart after annealing at 60° C.within 30 min in the oven.

TABLE 2 Summary of resin compositions. Low MW H- Low MW Control Low MWBonding Dynamic Name Loading (g) Loading (g) Loading (g) Loading (g)Monomer Composition Monomer 1 Butyl acrylate, (BA) 223.0 223.0 223.0223.0 Monomer 2 Methyl methacrylate, 262.9 262.9 262.9 262.9 (MMA)Monomer 3 Methacrylic acid, (MAA) 5.0 5.0 5.0 5.0 Monomer 4Methacrylamide, (MA) — — 4.9 — Monomer 5 Furfuryl Methacrylate, (FM) — —— 12.2 Total Monomer 490.9 490.9 495.8 503.1 Other IngredientsEmulsifier Rhodacal DS-10 (Solvay 5.9 5.9 5.9 5.9 Inc.) Initiator Sodiumpersulfate (SPS) 1.2 1.2 1.2 1.2 Base/Buffer Sodium carbonate 2.0 2.02.0 2.0 Defoamer BYK-022 0.1 0.1 0.1 0.1 Water DI water 496.2 496.2496.2 496.2 Chaser (reducer) Bruggolit FF6M 1.8 1.8 1.8 1.8 Chaser(oxidizer) Tert-butyl hydroperoxide 2.0 2.0 2.0 2.0 solution Chaintransfer 1-dodecanethiol — 24.5 24.5 24.5 agent Total weight (g) 1000.01024.5 1029.4 1036.7

TABLE 3 Hardness measurements for non-covalent self-healing resinsSpecialty Particle Pendulum Example Bulk CTA Specialty Monomer Wt % Vol.% Size Tg Hardness No. Monomers Ratio CTA Type Level Monomer LevelSolids Solids (nm) pH (° C.) 7 Days 1 BA/MMA 46/54 — — — — 48.3 46.1 1426.8 23.9 14 2 BA/MMA 46/54 DDT 5% — — 49.7 46.4 144 6.2 5.2 1 3 BA/MMA46/54 Butanethiol 5% — — 43.6 40.8 194 6.7 −17.0 0 4 BA/MMA 46/54 DDT 3%None NA 54.8 46.4 153 6.8 7.5 2 5 BA/MMA 46/54 DDT 5% Methacrylamide  1% 51.3 48.0 187 7.1 11.0 5 6 BA/MMA 46/54 DDT 3% Methacrylamide   1%50.5 47.7 119 6.9 7.4 6 7 BA/MMA 46/54 DDT 3% Methacrylamide 1.5% 50.344.9 154 6.9 — 6 8 BA/MMA 40/60 DDT 3% Methacrylamide   1% 51.8 47.7 1166.4 20.2 21 9 EHA/Sty 40/60 DDT 3% Methacrylamide   1% 53.2 49.3 159 6.812.1 2 10 EHA/Sty 30/70 DDT 3% Methacrylamide   1% 51.7 50.3 165 6.729.6 30 11 BA/MMA 46/54 — — Methacrylamide   1% 49.5 45.8 136 6.6 22. 14

TABLE 4 Healing results for non-covalent self-healing resins SpecialtyExample Bulk CTA Specialty Monomer No. Monomers Ratio CTA Type LevelMonomer Level Heals? Healing Conditions 1 BA/MMA 46/54 — — — — No 2BA/MMA 46/54 DDT 5% — — Yes — 55 C., 60 C., 70 C., 80 C., 3 h 5-10 min3-5 min 1 min 3 BA/MMA 46/54 Butanethiol 5% — — Yes — — 60 C., 70 C., 80C.,  3-5 min  2 min 1 min 4 BA/MMA 46/54 DDT 3% None NA Yes — 55 C., 60C., 70 C., 80 C., 3 h 5-10 min  1 min 30 sec 5 BA/MMA 46/54 DDT 5%Methacrylamide   1% Yes — — 60 C., 70 C., 80 C., 1 h 30 min 5 min 6BA/MMA 46/54 DDT 3% Methacrylamide   1% Yes 45 C., 55 C., 60 C., 70 C.,80 C., 40 h 1 h 5 min 3-5 min 1 min 7 BA/MMA 46/54 DDT 3% Methacrylamide1.5% Yes — — — — 80 C., 1 min 8 BA/MMA 40/60 DDT 3% Methacrylamide   1%Yes 45 C., 55 C., 60 C., 70 C., 80 C., 52 h 6 h 5-10 min  5 min 1 min 9ENA/Sty 40/60 DDT 3% Methacrylamide   1% Yes — — 60 C., 70 C., 80 C., 5min 3-5 min 30 sec 10 ENA/Sty 30/70 DDT 3% Methacrylamide   1% Yes — —60 C., 70 C., 80 C., 5-10 min  5 min 1 min 11 BA/MMA 46/54 — —Methacrylamide   1% No — — — — —

The results of the properties of resin compositions employing dynamiccovalent bonding were also evaluated. The compositions set forth inTable 5 were evaluated using a bismaleimide cross-linker(1,1′-(Methylenedi-4,1-phenylene)bismaleimide). Due to the insolubilityof the bismaleimide, the resins were first dried to remove the water.They were then redissolved in either THF or DMF and an appropriate levelof cross-linker was added with mixing. The samples were then cast fromthe solvent to yield dry films. The dry films were investigated fortheir self-hardness and healing properties as summarized in Tables 6 and7, respectively.

TABLE 5 Dynamic covalent bonding compositions. Specialty Example BulkCTA Specialty Monomer No. Monomers Ratio CTA Type Level Monomer LevelComment 12 BA/MMA 46/54 — — FM 2.5% 13 BA/MMA 46/54 DDT 3% FM 2.5% FMadded in last 30% PE 14 BA/MMA 46/54 DDT 3% FM 2.5% FM added in last 10%PE

TABLE 6 Hardness in resins before adding the bismaleimide cross-linker.Specialty Particle Pendulum Example Bulk CTA CTA Specialty Monomer Wt %Vol. % Size Tg Hardness No. Monomers Ratio Type Level Monomer LevelSolids Solids (nm) pH ( ° C.) 7 Days 12 BA/MMA 46/54 — — FM 2.5% 49.545.4 124 6.6 21.5 14 13 BA/MMA 46/54 DDT 3% FM 2.5% 49.6 45.9 161 6.87.2 6 14 BA/MMA 46/54 DDT 3% FM 2.5% 47.9 44.7 180 6.8 7.2 7

TABLE 7 Self-healing in resins using dynamic covalent bonding. ResinCross- Example Sample Cross-linker Solvent linker Healing HardnessHardness No. No. Type for BM Level Tg Heals? Conditions 7 day 1 month 1512 Bismaleimide DMF   5% 21.5 No — 15 17 16 13 Bismaleimide DMF 1.25%2.34 Yes 60 C., 10 min 5 7 17 14 Bismaleimide DMF 1.25% 4.25 Yes 60 C.,10 min 5 7 18 14 Bismaleimide DMF 2.32% 4.25 Yes 60 C., 10 min 7 14 1914 Bismaleimide THF 2.32% — Yes 60 C., 10 min 4 7

Paint Formulas Containing Self-Healing Non-Covalent Resins

The resins were evaluated in Behr Premium Plus High Gloss 8300. Theexisting resin was replaced with self-healing resin Example 6 andExample 8. No coalescent was necessary in the batches containingself-healing resin for complete film formation at 40° F. The standardmethod is used to produce the paint formulations except the substitutionof the resin with the respective self-healing resins. Film of DFT 5-8mil is used for confirming self healing performance. Film with Example 6heals within 45-60 min at 60-65° C. and if heals by hair dryer takes 30min whereas Example 8 takes 60 min at 60-65° C. and with hair dryer ittakes 10 min for healing. CTR has no healing performance even if exposedto higher temperature of 120-150° C.

The resins were evaluated in Behr Wet-Look Sealer 985. The existingresin was replaced with self-healing resin Example 6 and Example 8, asbatch 3 and 4, respectively. No coalescent was necessary in the batchescontaining self-healing resin. The standard method is used to producethe paint formulations except the substitution of the resin with therespective self-healing resins. Batch 3 & 4 along with CTR applied onmetal of 5-8 mil DFT and on Quarry tile by brush and tried to maintaineduniform film formation. Films dried for 3 days at room temperaturebefore checking self healing performance. Film cut ‘X’ with sharp cutterand deep scratch made on panel. On metal as well as on quarry tile withhair dryer ,batch 3 takes 10 min whereas batch 4 takes 5 min forhealing, Quary tile kept in oven for healing at 60-65° C., healingobserved within 20-25 min whereas the metal panel kept over heatingplate under controlled temperature of 60-65° C. and healing observedwithin 30 min. CTR does not have any healing performance even if exposedto high temperature 120-150° C.

The resins were also evaluated in Behr Premium Waterproofing Wood Finish500. The existing resin was replaced with self-healing resin Example 6and Example 8, as batch 5 and 6, respectively. No coalescent wasnecessary in the batches containing self-healing resin. The standardmethod is used to produce the paint formulations except the substitutionof the resin with the respective self-healing resins. Self-healing wasobserved in these samples. The coating prepared with thickness of 5-8mil DFT on wood, dried for 3 days before test. Performed self healing byusing hair dryer, batch 5 & 6 takes 10-15 min for healing on wood and at60-65° C. takes 30 min whereas CTR does not heal even when exposed at60-65° C. for 48 hrs

In order to evaluate the self-healing property of the resin, a samplewas applied to a metal panel with square bar (BYK) of 15-20 mil WFT soto yield a final dry film of 5-8 mil. Film can also be formed by usingfoam brush or nylon brush to achieve 5-8 mil dry film. The film was thendried for various times (24 h, 3 day, 7 day) and then scratched with an“X” using a sharp knife. The scratch was deep enough to only penetratethe film and not the substrate. The healing was then monitored using apre-set temperature on a heating plate or in an oven such as 45, 55, 60,70, 85° C. while monitoring the self-healing at different temperatureand time. Healing can also be done by using a standard hair dryer whichoperates at approximately 70 to 80° C. Self-healing was also observedwhen panels were placed outside in sunlight. The sunlight caused thetemperature to rise sufficiently for self-healing to occur. The panelswere prepared similar as mentioned above. Testing was done on metal,wood and concrete by keeping the substrate in a horizontal position. Thesubstrate temperature and healing time was monitored. Healing typicallyoccurred within 2-4 hrs. Considering the temperature of the substrate at53-60° C.

While exemplary embodiments are described above, it is not intended thatthese embodiments describe all possible forms of the invention. Rather,the words used in the specification are words of description rather thanlimitation, and it is understood that various changes may be madewithout departing from the spirit and scope of the invention.Additionally, the features of various implementing embodiments,variations, and refinements may be combined to form further embodimentsof the invention.

What is claimed is:
 1. A self-healing resin comprising: a self-healingpolymer having a first functional group and a second functional groupbonded thereto, the first functional group and the second functionalgroup interacting with each other by dynamic covalent or dynamicnon-covalent interactions, at least one of the first functional groupand the second functional group being present in an amount of 0.1 to 10mole percent the self-healing polymer having a weight average molecularweight of about 15,000 g/mol to 1,000,000 g/mol.
 2. The self-healingresin of claim 1, wherein the weight average molecular weight of theself-healing polymer is such that the self-healing polymer dissolves inacetone with solubility greater than 0.1 g/ml at 25° C.
 3. Theself-healing resin of claim 1 wherein the self-healing polymer has amolecular weight less than 1,000,000.
 4. The self-healing resin of claim1 wherein the self-healing polymer is an emulsion self-healing polymer.5. The self-healing resin of claim 1 wherein self-healing polymersegments interact by hydrogen bonding, electrostatic, metal-ligandinteractions, reversible covalent bonds, or combinations thereof.
 6. Theself-healing resin of claims 1 wherein dynamic covalent or dynamicnon-covalent interactions are triggered by an external stimulus.
 7. Theself-healing resin of claim 6 wherein the dynamic covalent or dynamicnon-covalent interactions are triggered by light, heat, redox, or achange in pH.
 8. The self-healing resin of claim 1 further including aresidue of a chain transfer agent that reduces the molecular weight ofself-healing polymer chains in the self-healing polymer.
 9. Theself-healing resin of claim 8 wherein the chain transfer agent is aC₁₋₁₅ thiol.
 10. The self-healing resin of claim 9 wherein the chaintransfer agent is selected from the group consisting of octanethiol,butanethiol, thioglycolic acid, Z-thioethanol, methanethiol,ethanethiol, propanethiol, pentanethiol, hexanethiol, heptanethiol,nonanethiol, decanethiol, dodecanethiol, and combinations thereof. 11.The self-healing resin of claim 1 wherein the self-healing polymer isformed by one or more monomers or functionalized derivative of monomersselected from the group consisting of acrylic acid, methacrylic acid,methacrylate, methyl acrylate, ethyl acrylate, 2-chloroethyl vinylether, 2-ethylhexyl acrylate, hydroxyethyl methacrylate, butyl acrylate,butyl methacrylate, trimethylolpropane triacrylate, methacrylate,pentafluorophenyl methacrylate bis-(2,2,2-trifluoroethyl) itaconate,bis-(1,1,1,3,3,3-hexafluoroisopropyl) acrylate, 1H,1H,3H-hexafluorobutylacrylate, 1H,1H,7H-dodecafluoroheptyl methacrylate, 2,2,2-trifluoroethylacrylate, 2,2,2-trifluoroethyl methacrylate, aliphatic,bis-(2,2,2-trifluoroethyl) itaconate,bis-(1,1,1,3,3,3-hexafluoroisopropyl) acrylate, 1H,1H,3H-hexafluorobutylacrylate, 1H,1H,7H-dodecafluoroheptyl methacrylate, 2,2,2-trifluoroethylacrylate, 2,2,2-trifluoroethyl methacrylate, pentafluorophenyl acrylate,1,1,1,3,3,3-hexafluoroisopropyl acrylate,1H,1H,2H,2H-Heptadecafluorodecyl methacrylate acrylic,1H,1H,2H,2H-heptadecafluorodecyl acrylate, 1H,1H,5H-octafluoropentylacrylate, 1H,1H,3H-tetrafluoropropyl methacrylate, hexafluoro-iso-propylmethacrylate, 1H,1H,3H-hexafluorobutyl methacrylate,1H,1H,5H-octafluoropentyl, ethylene, propylene, 1-butylene, 2 butylene,vinyl acetate, and combinations thereof, such that from 0.1 to 5 weightpercent of the monomers have a functional group that covalently bondedto the self-healing polymer that interact with each other by dynamiccovalent or dynamic non-covalent interactions, the monomers whenfunctionalized being functionalized with OH, halo, or combinationsthereof
 12. A paint composition comprising: water; a self-healingpolymer having a first functional group and a second functional groupbonded thereto, the first functional group and the second functionalgroup interacting with each other by dynamic covalent or dynamicnon-covalent interactions, at least one of the first functional groupand the second functional group being present in an amount of 0.1 to 10mole percent the self-healing polymer having a weight average molecularweight of about 15,000 g/mol to 1,000,000 g/mol; and one or moreoptional pigment compositions.
 13. The paint composition of claim 12wherein the weight average molecular weight of the self-healing polymeris such that the self-healing polymer dissolves in acetone with asolubility greater than 0.1 g/ml at 25° C.
 14. The paint composition ofclaim 12 wherein the self-healing polymer has a molecular weight lessthan 1,000,000.
 15. The paint composition of claim 12 wherein theself-healing polymer is an emulsion self-healing polymer.
 16. The paintcomposition of claim 12 wherein self-healing polymer segments interactby hydrogen bonding, electrostatic, metal-ligand interactions,reversible covalent bonds, or combinations thereof.
 17. The paintcomposition of claims 12 wherein dynamic covalent or dynamicnon-covalent interactions are triggered by an external stimulus.
 18. Thepaint composition of claim 17 wherein the dynamic covalent or dynamicnon-covalent interactions are triggered by light, heat, redox, or achange in pH.
 19. The paint composition of claim 12 further including aresidue of a chain transfer agent that reduces the molecular weight ofself-healing polymer chains in the self-healing polymer.
 20. The paintcomposition of claim 19 wherein the chain transfer agent is a C₁₋₁₅thiol.
 21. The paint composition of claim 12 wherein the chain transferagent is selected from the group consisting of octanethiol, butanethiol,thioglycolic acid, Z-thioethanol, methanethiol, ethanethiol,propanethiol, pentanethiol, hexanethiol, heptanethiol, nonanethiol,decanethiol, dodecanethiol, and combinations thereof.
 22. The paintcomposition of claim 12 wherein the self-healing polymer is formed byone or more monomers or functionalized derivatives of monomers selectedfrom the group consisting of acrylic acid, methacrylic acid,methacrylate, methyl acrylate, ethyl acrylate, 2-chloroethyl vinylether, 2-ethylhexyl acrylate, hydroxyethyl methacrylate, butyl acrylate,butyl methacrylate, trimethylolpropane triacrylate, methacrylate,pentafluorophenyl methacrylate bis-(2,2,2-trifluoroethyl) itaconate,bis-(1,1,1,3,3,3-hexafluoroisopropyl) acrylate, 1H,1H,3H-hexafluorobutylacrylate, 1H,1H,7H-dodecafluoroheptyl methacrylate, 2,2,2-trifluoroethylacrylate, 2,2,2-trifluoroethyl methacrylate, aliphatic,bis-(2,2,2-trifluoroethyl) itaconate,bis-(1,1,1,3,3,3-hexafluoroisopropyl) acrylate, 1H,1H,3H-hexafluorobutylacrylate, 1H,1H,7H-dodecafluoroheptyl methacrylate, 2,2,2-trifluoroethylacrylate, 2,2,2-trifluoroethyl methacrylate, pentafluorophenyl acrylate,1,1,1,3,3,3-hexafluoroisopropyl acrylate,1H,1H,2H,2H-Heptadecafluorodecyl methacrylate acrylic,1H,1H,2H,2H-heptadecafluorodecyl acrylate, 1H,1H,5H-octafluoropentylacrylate, 1H,1H,3H-tetrafluoropropyl methacrylate, hexafluoro-iso-propylmethacrylate, 1H,1H,3H-hexafluorobutyl methacrylate,1H,1H,5H-octafluoropentyl, ethylene, propylene, 1-butylene, 2 butylene,vinyl acetate, and combinations thereof, such that from 0.1 to 5 weightpercent of the monomers have a functional group that covalently bondedto the self-healing polymer that interact with each other by dynamiccovalent or dynamic non-covalent interactions.
 23. The paint compositionof claim 12 wherein the monomers are functionalized with OH, halo, orcombinations thereof.